Automatic circuit-breaker.



UNITED STATES PATENT OFFICE.

CHARLES M. CLARK, OF NENV YORK, N. Y.

AUTOMATICk vCIRCUIT-BREAKER.

SPECIFICATION forming part of Letters Patent No. 628,762, dated July' l1, 1899.

Application filed January 23, 1899. Serial No. 703,099. (No model.)

To LU who/lb t muy conce/'n.-

Be it known that I, CHARLEs M. CLARK, of the city of New York, borough of Brooklyn, in the county of Kings and 'State of New York, have invented a new andlmprovedriu tornatic Circuit-Breaker, ci which the following is a full, clear, and exact description.

The invention relates to automatic magnetic circuit-breakers such as shown and described in the Letters Patent of the United States No. 616,405, granted to me on December 20, 1898.

The object of the present invention is to provide a new and improved automatic circuit-breaker which is simple and durable in construction, verysensitive in operation, and arranged to break the circuit without danger of sparking immediately upon the current breaking when becoming either underloaded or overloaded.

The invention consists of novel features and parts and combinations of the same, as will be fully described hereinafter and then pointed out in the claims.

A practical embodiment ot my invention is represented in the accompanying drawings, forming a part of this specification, in which similar characters ot' reference indicate corresponding parts in all the views.

a transverse section of the saine on the line .t2 2 in Fig. l, and Fig. 3 is a diagrammatic view of a modified form ol the improvement.

The improved automatic circuit-breaker is mounted in a suitably-constructed casing A, having a cover A' provided with glass panes A2 to permit of conveniently examining the working of the apparatus located in the casing without opening the cover.

On the casing A, preferably at one sido thereof, are arranged the binding-posts B B, connected with the ends of the wire forming a circuit, the bindingepost B being connected by a wire C with a brush D, secured on one side of a block E, of insulating material, and secured to the top of the casing, as is plainly illustrated in the drawings. The free end of the brush D is in contact with one side of a metallic block F, secured in the web of a disk G, preferably made of iron covered with agate, enamel, or other insulating material for insulating the iron, the disk being secured on a shaft H, mounted to tu rn in the casing. The blockV F is adapted to be engaged at its other side by a brush D, likewise secured to the block F. and connected by a wire C with an electromagnetlof the usual construction and from which leads a wire C2 back to the binding-post B', an electromagnet J being in said wire foractuating the apparatus on an underload, as hereinafter more fully described, it being understood thata solenoid or other device may be used instead of the electromag net J.

The electromagnet I is provided with apivoted armature l', connected by'a link K with a lever L, the shaft N of which is mounted to turn in suitable bearings in the casing A, and on said shaft is fulcrumed loosely a latch O, adapted to engage a pin G2, projecting from the face of the disk G, so as to lock the latter against rotation by its helical spring P and to normally hold the disk iu such position that the block F is in contact with both brushes D D. When the latch O is swung out of engagement with the pin G2, then the disk G is y free to revolve in the direction ot the arrow a' by the action of the helical spring P to move the block F out of engagement with the Q brushes D D' and break the circuit.

Figure l is a sectional front elevation ot the improvement on theline ll in Fig. i3. Fig. 2 is The core ofthe electromagnet J is arranged directly above the free end of the latch O above the top thereof, and the under side of the free end of said latch is engaged by a spring Q, held on a screw-rod Q, adjustable in the lever L to permit of regulating the tension of said spring Q. The tendency ot the spring Q is to swing the latch O out of engagement with the pin G2, while the electromagnet J tends to hold the said latch normally in engagement with the pin G2, it being understood that the elcctromagnet J and the spring Q normally about counterbalance each other; but in case of an underload in the current passing` through the electromagnet the 'force of the electromagiietis correspondingly reduced., and the spring Q, can now impart a swinging motion to the latch O to disengage the same from the pin G2 and unlock the disk G to allow the same'to turn by the action of .the spring P and break the circuit, as before IOO with a lug L, adapted to engagea correspond- 'ing lng O' on the fulcrum end of the latch O, so that when the lever L is swung downward in the direction of the arrow b' at the time the electroinagnet I .is energized on an overload of the current, then the lng L', by engaging the lug O, swings the latch O out of engagement with the pin G2 to unlock the disk and permit the latter to turn in the direct-ion of the arrow a to break the circuit. It is understood that the electromagnet l does not energize sufficiently to attract its armature l as long as the current is of a norma-l force; but as soon as the current becomes excessive the armature l is attracted for releasing the disk G by the action of the lever L and the latch O, as above described.

rlhe core of the electroinagnet, as well as the lever L, may be laminated in case alternating currents are used instead of direct ones.

rlhe lever L is normally held in the position shown in Fig. l by the action of a spring R, connected with an adiusting-bolt R, screwed in the casing, to permit of regulating the tension of the spring according to the strength of the current for which the apparatus is set. The lever L is adapted to be engaged by a rod S, iittcd to slide in suitable bearings in the casing A, the upper end of the said rod extending to the outside of the casing, the rod being normally hcld in an uppermost position, as shown in Fig. l, bythe action of a spring S', coiled on said rod. The outer end of the rod S is provided with a suitable handle or knob Si, adapted to be taken hold of by the operator and pressed to slide the rod downward and move it in engagement with the lever L, so as to impart a swinging motion thereto in the direction of the arrow L for throwing the latch O ont of engagement with the pin G`2 whenever it is desired to break the circuit. 'lhis arrangement forms a switch for the circnit-breal;er to allow the operator to break the circuit whenever de sired.

In order to prevent resetting of the machine by the operator before thc excessive current is turned oft, l provide an arrangementsimilar to that described in the patent. previously referred to, the construction being as follows: The shaft H, carrying the disk G, is mounted to turn at one end in a bearing AS, attached tothe back of the casing A, the other end of the shaft being coupled to a shaft H', mounted to turn in bearings formed in the cover A', as indicated in Fig. A hand-wheel lil2 is secured to the outer end of the shaft H for allowing` the operator to reset the machine, and the coupling between the shafts H and H consists of a spring-pressed pawl H3, fulcrumed on the shaft H and formed with alug H4, normally engaging a notch HF in the periphery of a collar H, formed or secured on the inner end of the shaft HC The free end of the pawl H3 is adapted to be engaged by an arm L2, extending from the lever L, so that when the operator turns the hand-wheel lle to reset the machine before the excessive current is turned olf then the lever L is immediately actuated again and the arm Limparts a swinging motion to the pawl lli", so as to disengage the lng HVL thereof from the notch Il and allow the spring l of the disk to again rotate the same in the direction of the arrow o.' to break the circuit. 'lhns the shafts H Hl are automatically disconnected, and the machine cannot be reset unless excessive current is shut oli.

As indicated in the drawings, the shaft N for the lever L extends through a segmental slot G' in the disk G; but it is understood that this is not essential, as 'the shaft maybe journaled in bearings On one side of the disk.

In order to break the force of the tinal rotary motion of the disk G after the circuit is broken and before the wall of the slot G' comes in contact with the shaft N, l provide a spring T, secured on a suitable block T', attached te the casing, the free end projecting into the path of an offset or shoulder G, formed on the disk G. (See Fig. l.) Thus when the latch O disengnges the pin G2 and the helical spring P rotates the disk G in the direction of the arrow o.' then the shoulder G3 finally comes in contact with the spring T, which is compressed, and brings the disk to a gradual stop.

rhe blow-out device for preveiiting arcing at the time the circuit is broken consists ol an L-sliaped plate U, of enameled iron and secured to the inside of the casing A. The plate U is formed with a longitudinal slot t0 produce two forked members straddling the disk Gatitstaces,tl1e horizontal members of the plate extending iinine .liatcly below the lower edges of the brushes and the vertical member extending at one side of the brushes, as will be readily understood by reference to Figs. l and 2. The horizontal members ofthe plate prevent a possible downward jumping ol' the arc to the detriment of working parts ofthe apparatus located below said inem bers.

It is evident that when the disk G is ro- ICO IIO

tated for breaking the circuit the spark pro 115 duced by the block F leaving the free ends of the brushes is readily extinguished by the blow-out plate U.

The operation is as follows: AS long as the current is normal the several parts` remain in the position shown in Figs. l and and the circuit passes from the binding-post B by the wire C, brush D, block F, brush D', wire C', electroniaguet l, wire G2, and elcctromagnet .l to the binding-post D. lYhen an excessive current passes through the circuit, as described, then thc electromagnet I is energized to such an extent that the armature l' is attracted and the latch O is thrown ont of engagement with the pin G2 to allow the spring P to rotate the disk G in the direction of the arrow c', as previously described, to move the block F out of engagement with the brushes D D and break the circuit. ln case of an undercurrent the attractive force of the electromagnet .I decreases to such an extent that the spring Q overbalances and throws the latch O out of engagement with the pin G2 to unlock the disk and allow its spring to rotate and to break the circuit in the manner previously described. In case the operator desires to break the circuit he simply presses the knob S2, as above explained. It is understood that after the current is broken and the excessive current is shut oil' the operator can reset the device by turning the hand-wheel H2 in the inverse direction oi the arrow d to bring the several parts back into position, as above described, and illustrated in Figs. 1 and 2.

By the arrangement described the strength ot' the current controls the electromagnet J, so that the under-load arrangement is actuated upon a decrease oi' the strength of the current; but in order to actuate the device on an underload according to a decrease in the voltage I use the arrangement shown in Fig.

3, in which the electromagnet J is connected bya wire C3 with the wire C' and with a separate binding-post B2. The electromagnet .I counterbalances the spring Q until a decrease in the voltage of the current takes place. The current passing through the wire C3 is entirely dependent on the electromotive force of the current, since the coil J is shunted across the circuit to receive thefull electromotive force of the line irrespective of the strength of the current. It the electromotive force weakens from any cause, it is evident that the coll J is proportionately7 weakened and causes a release ot' the disk by the mechanism described. IE the voltage increases, it increases the coil J, but does not actuate it.

The block F may have its forward end made oi carbon or other material, so that iinal breaking of the circuit takes place after the metal block has left the brushes and the carbon is about to leave the same. This arrangement is serviceable for heavy currents.

In machines for overloads only the electromagnet J is dispensed with, and the spring Q, is then made a push-spring instead of a pullspring, as shown and described. Itis, however, understood that in either case the construction of the latch-lever and spring is made use of, as it permits easy engagement of the latch with the pin on resetting irrespective of the lever. The block F projects a suitable distance on the faces ot the disk to make proper contact with the free ends of the brushes, the said free ends being thus prevented from coming into contact with and scraping the face of the disk G.

It is understood that two or more disks may be employed or that in one disk two or more contact-blocks may be placed and so arranged that one will break the contact with CIJ its brushes previous to the other, which will make the final break. In this case it is preferable to make the second block of platinum or the like, as it is not liable to fuse or melt by the arc.

Having thus fully described my invention, I claim as new and desire to secure by Letters Patent-- l. A circuit-breaker, provided with a springpressed rotary disk normally in position to render the circuit continuous, an electromagnet in the circuit and arranged for action on an overload oi' current, a spring-pressed latch for normally locking the disk against the tension of its spring, a connection between the latch and the electromagnet for actuating the latch and unlocking the disk upon an overload of current and an electromagnet for the latch, and likewise in the circuit for movably holding the latch in a locking position relatively to the disk and for permitting the spring of the latch to actuate the latter and unlock the disk upon the passing` of an underload ot current, substantially as shown and described.

2. A circuit-breaker, comprising a springpressed rotary insulated disk, a contact-block seated in the disk, fixed brushes normally engaging the said block on each side of the disk, said brushes being in an electric circuit, an electromagnet in the circuit and arranged for action on an overload of current, a springpressed latch for normally locking the disk against the tension of its spring, a connection between the latch and the electromagnet, for actuating the latch and unlocking the disk upon an overload of current, and an electromagnet for the latch, and likewise in the circuit for normally holding the latch in a locking position relatively to the disk, and for permitting the spring of the latch to actua're the latter and disengage or unlock the disk upon an underload ot' current passing through the solenoid, substantially as shown and described.

3. A circuit-breaker provided with a springpressed rotary disk normally in position to render the circuit continuous,a latch for locking the disk against rotation by its spring, a spring for drawing t-he latch out of a locking position relatively to said disk, and a device controlled by the current and in which no break of the current occurs, for counterbalancing the action of said spring, to hold the latch normally in a locked position, and to allow the spring to move the latch out of a locked position upon a decrease of current or drop in voltage, substantially as shown and described.

CHARLES M. CLARK.

Witnesses:

THEO. G. Hosrnn, Evnannn BOLTON MARSHALL.

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